Straightener

ABSTRACT

A straightener in which the shape of guide bar facings is simplified and the guide bar facings are effectively used.  
     In the straightener, a clearance (S) opening in a direction orthogonal to a line connecting the axes of straightening rolls ( 12, 14 ) to each other in a plane orthogonal to a carrying route is formed between the vertically opposed straightening rolls ( 12, 14 ). The pair of guide bar facings ( 30, 30 ) guiding a work material (W) are formed in generally rectangular flat plate shapes, and disposed on the inlet side and the outlet side for the work material (W) of both straightening rolls ( 12, 14 ). Also, the guide bar facings ( 30 ) are disposed aslant relative to a carrying face (PL) along the opening direction of the clearance (S) so as not to be interfered with both straightening rolls ( 12, 14 ). The guide faces ( 321 ) of the guide bar facings ( 30 ) are formed such that the guide bar facings ( 30 ) can be linearly moved forward and backward along the opening direction of the clearance (S) relative to the carrying route in the state of facing the carrying route parallel with each other through the clearance (S).

TECHNICAL FIELD

The present invention relates to a straightener which lets a work material, such as a round rod or steel pipe, having kinks, bends or the like thereon, to pass between a pair of straightening rolls to be straightened.

BACKGROUND ART

In a process of working a rod-like material (hereinafter called “work material”) such as a round rod or steel pipe, a so-called rod straightener is widely used as means for straightening kinks, bends or the like on the work material. As schematically shown in FIG. 8, the rod straightener has a pair of straightening rolls 12, 14 positioned one above the other, with a horizontal carrying route for a work material W in between, and disposed so as to cross each other at a predetermined angle to the carrying route. The lower and upper straightening rolls 12, 14 are rotated in a predetermined direction by unillustrated drive means. A pair of material guide members (hereinafter called “guide bar facings”) 16, 16 are horizontally disposed on both sides of the carrying route, respectively (see Patent Document 1, for example). As the work material W is enforced to pass between both straightening rolls 12, 14, bends or the like are straightened and the work material W is smoothly guided by the guide bar facings 16, 16 disposed opposite each other.

Each guide bar facing 16 is secured in a detachable and replaceable manner to the front end face of a guide bar 18 having a horizontally rectangular shape and disposed in a direction along the carrying route. The guide bar facings 16, 16 serve to guide the work material W in the correct moving direction during the straightening work. As the guide bar facings 16, 16 contact the work material W while guiding it and has a large load applied thereto, however, a guide face 16 a in contact with the work material W wears out with time, and eventually loses the intended guiding performance. It is therefore necessary to frequently detach the guide bar facings 16, 16 from the guide bars 18 for replacement with new ones in accordance with the progressing wear-out of the guide bar facings 16, 16. This increases the running cost.

In this respect, the guide bar 18 is so configured as to be movable forward and backward in a direction crossing the carrying route by an adequate forward/backward moving mechanism (not shown), so that the guide bars 18, 18 are moved in the direction crossing the carrying route according to the progressing wear-out of the guide bar facings 16, 16 to maintain the correlation between the guide bar facings 16, 16 and the work material W and secure the guide performance.

-   Patent Document 1: Japanese Utility Model Laid-Open Publication No.     H6-39217

DISCLOSURE OF INVENTION Problems to be Solved by the Invention

The circumferential surfaces of the body portions of both straightening rolls 12, 14 are formed in a recess form (tsuzumi shape) in the axial direction, with the straightening rolls 12, 14 disposed opposite to each other crossing their axes at a predetermined angle. That is, at the roll's center portion where the axes of both straightening rolls 12, 14 cross each other, each straightening roll 12, 14 does not protrude toward the other straightening roll 14, 12 with respect to a carrying face PL of the work material W, and there is a clearance S opening in the horizontal direction (see FIG. 9), while at the axial-directional end portion of the straightening roll 12, 14, one of the lower and upper straightening rolls 12, 14 protrudes toward the carrying face PL (see FIG. 10(a)). If the guide bar facings 16, 16 are merely inserted in the clearance S between the lower and upper straightening rolls 12, 14 from the horizontal direction with respect to the carrying route, the guide bar facings 16, 16 interfere with one of the lower and upper straightening rolls 12, 14. The interference of both straightening rolls 12, 14 can be avoided by forming the guide bar facings 16, 16 in a three-dimensionally complex shape of being curved according to the circumferential surfaces of the body portions of the straightening rolls 12, 14 which may interfere. The complex shape increases the cost of the guide bar facing 16 itself, and disadvantageously increases the weight thereof.

With the structure that moves the guide bar 18 forward toward the carrying route according to the progressing wear-out of the guide bar facing 16, as mentioned above, the guide bar facing 16 even with the three-dimensional shape interferes with one of the lower and upper straightening rolls 12, 14 with the passage of time according to the forward movement of the guide bar facing 16, so that a large amount of wear tolerance of the guide bar facing 16 cannot be provided (see FIG. 10(b)). While there is a large margin left for the size of the guide bar facing 16 in the direction to cross the carrying route, therefore, the guide bar facing 16 needs frequent replacement. Further, the position of the guide face 16 a of the guide bar facing 16, which abuts on the work material W, with respect to the work material W is shifted with the forward movement of the guide bar facing 16, the guide performance becomes lower and the surface of the work material W may be scratched, thus raising a problem on the straightening quality.

The work material W is fed while twisted in a predetermined direction by the rotation of the both straightening rolls 12, 14, and its askew movement applies force to the guide bar facings 16, 16. That is, there is the disadvantage pointed out that the inlet side of one of the guide bar facings 16 and the outlet side of the other guide bar facing 16 locally wear out, so that the guide bar facings 16, 16 as a whole cannot be used effectively, thus shortening the life thereof.

In consideration of the inherent problems of the straightener according to the related art, therefore, the present invention has been proposed to suitably overcome the problems, and aims at providing a straightener capable of preventing interference between a guide bar facing and a straightening roll and effectively using the guide bar facing.

Means for Solving the Problems

To overcome the problems and achieve the intended object, a straightener according to the present invention has a pair of straightening rolls facing each other, one above the other, with a carrying route for a work material in between, provided so as to cross each other at a predetermined angle to the carrying route, and formed in a tsuzumi shape having at least one circumferential surface recessed, and a pair of guide bar facings which are disposed facing each other along the carrying route for the work material so as to intersect an opposing direction of the straightening rolls and guide the work material, with a clearance formed between both straightening rolls and opening in a direction orthogonal to a line connecting axes of the straightening rolls to each other in a plane orthogonal, to the carrying route, and is characterized in that

the pair of guide bar facings are each formed in an approximately rectangular flat plate and are respectively provided at an inlet-side area and an outlet-side area of both straightening rolls for the work material,

each of the guide bar facings is disposed askew to a horizontal carrying face of the work material along an opening direction of the clearance so as not to interfere with both straightening rolls, and

guide faces of the guide bar facings for the work material are formed in such a way that the guide bar facings are linearly movable forward and backward along the opening direction of the clearance relative to the carrying route in a state where the guide faces face the carrying route in parallel to each other through the clearance.

Effect of the Invention

According to the present invention, a pair of guide bar facings are formed in the form of an approximately rectangular flat plate, and are respectively disposed at the inlet-side area and the outlet-side area of both straightening rolls for the work material, each guide bar facing is disposed askew to the horizontal carrying face of the work material along the opening direction of the clearance so as not to interfere with both straightening rolls, and the guide faces of the guide bar facings for the work material are formed in such a way that the guide bar facings are linearly movable forward and backward along the opening direction of the clearance relative to the carrying route in a state where the guide faces face the carrying route in parallel to each other through the clearance. This makes it possible to avoid the interference between the guide bar facing with the straightening roll, simplify the shape of the guide bar facing, and make the best use of the size of the guide bar facing in the direction to cross the carrying route. One of the guide bar facings which corresponds to a direction of movement caused by twisting of the work material is formed wider along the carrying route than the other paired guide bar facing, thereby elongating the service life of the guide bar facing which locally wears out due to twisting of the work material and ensuring suitable guiding of that area where there is a large degree of slide contact with the work material. Further, a forward/backward moving mechanism which moves the guide bar facing forward and backward along the opening direction of the clearance is provided with a whirl-stop mechanism, thereby preventing the position of the guide bar facing from being shifted relative to the carrying route.

BRIEF DESCRIPTION OF DRAWING

FIG. 1 is a plan view showing straightening rolls of a straightener according to a preferable embodiment of the present invention.

FIG. 2 is a front view showing the straightening rolls of the straightener of the embodiment.

FIG. 3 is a plan view showing material guide means of the straightener of the embodiment.

FIG. 4 is a side view showing the material guide means of the straightener of the embodiment, with a two-dot chain line showing a cross section along line X-X in FIG. 1, a three-dot chain line showing a cross section along line Y-Y in FIG. 1, and a dotted line showing a cross section along line Z-Z in FIG. 1.

FIG. 5(a) shows the cross section along line X-X in FIG. 1, 5(b) shows the cross section along line Y-Y in FIG. 1, and 5(c) shows the cross section along line Z-Z in FIG. 1.

FIG. 6 is a plan view showing material guide means of a straightener according to a modification.

FIG. 7 is a side view showing the material guide means of the straightener of the modification.

FIG. 8 is a plan view showing straightening rolls of a conventional straightener.

FIG. 9 is a cross-sectional view line A-A in FIG. 8.

FIG. 10 is a cross-sectional view line B-B in FIG. 8, 10(a) showing a state where the use of the guide bar facings is started, and 10(b) showing the state where the use of the guide bar facings is being used, with four marks X indicating interfering portions.

BEST MODE FOR CARRYING OUT THE INVENTION

A preferred embodiment of a straightener according to the present invention will now be described with reference to the accompanying drawings. For the sake of descriptive convenience, the same constituting elements as those of the straightener shown in FIGS. 8 to 10 will be given the same reference symbols to omit a detailed description thereof.

EMBODIMENT

In a process of working a work material W such as a round rod or steel pipe, a straightener serving as means for straightening kinks, bends or the like on the work material W has a pair of straightening rolls 12, 14 positioned one above the other, with a horizontal carrying route for the work material W in between as shown in FIG. 1 or 2. As schematically shown by the oblique one-dot chain line in FIG. 1, the individual straightening rolls 12, 14 have their axes crossing each other at a predetermined angle to the carrying route for the work material W (approximately 30° from the carrying route in the embodiment) and are so supported as to cross each other in an X pattern. The circumferential surface of the body portion of the lower straightening roll 12 of the embodiment is formed in a recess form (tsuzumi shape) in the axial direction. Likewise, the circumferential surface of the body portion of the upper straightening roll 14 is formed in a recess form (tsuzumi shape) in the axial direction. The lower and upper straightening rolls 12, 14 are disposed so that the intersection of the axes is positioned above the carrying route, and the top surface of the body portion of the lower straightening roll 12 where the work material W is mounted serves as a carrying face PL as a horizontal reference plane at the time of feeding the work material W. The straightening rolls 12, 14 are rotated in a predetermined direction by unillustrated roll drive mechanisms, so that the work material W which passes pressed between both straightening rolls 12, 14 is fed while being twisted in the predetermined direction according to the rotational direction of the straightening rolls 12, 14. With the lower straightening roll 12 being taken as a reference, the upper straightening roll 14 is displaceable and adjustable in the up and down direction according to the diameter of the work material W.

A clearance S opening in a direction orthogonal to a line connecting the axes of the straightening rolls 12, 14 to each other in a plane orthogonal to the carrying route is formed between both straightening rolls 12, 14 disposed one above the other (see FIG. 5). That is, because on that side where the axis of each straightening roll 12, 14 goes away from the carrying route, the periphery of each straightening roll 12, 14 protrudes more toward the other straightening roll 14, 12 than the carrying route, the clearance S opening askew to the horizontal carrying face PL of the work material W is formed between both straightening rolls 12, 14 on that side.

As shown in FIG. 3, the straightener has a pair of holders 24, 24 (only one shown) symmetrically disposed facing each other with the carrying route for the work material W in between. As the holders 24 are pivotably supported on the main body of the straightener in an openable and closable manner, the holders 24 function as a so-called door. The straightener has a pair of columnar supports 20, 20 (only one shown) provided upright vertically. The holder 24 made of a rectangular plate member is pivotably and rotatably supported on the right columnar support 20 via a cylindrical support member 26 provided at one lengthwise end. The support member 26 is disposed slidable in the axial direction with respect to the columnar support 20, and is configured so that the vertical height of the holder 24 can be adjusted by an unillustrated elevation mechanism. The holder 24, which is normally closed, is opened and closed by an unillustrated holder opening/closing mechanism.

Material guide means 28 which basically includes a guide bar facing 30, a guide bar 34 and a forward/backward moving mechanism 40 and guides the work material W along the carrying route is provided at the holder 24. As shown in FIG. 3 or FIG. 4, a plurality of (two in the embodiment) guide bars 34 having an horizontally elongated rectangular shape are provided on the inner surface of the holder 24 that faces the carrying route, via the forward/backward moving mechanisms 40, respectively, with the guide bar facing 30 secured to the front end face of each guide bar 34 in a detachable and replaceable manner. Two sets of guide bar facings 30 are disposed on both the front and rear sides of the carrying route for the work material W along the carrying route. As the work material W is held by a pair of guide bar facings 30, 30 facing each other with the carrying route in between, the work material W is smoothly guided (see FIG. 1). That is, each holder 24, 24 of the embodiment has two material guide means 28, 28. The guide bar 34 can be linearly moved forward and backward in a direction crossing the carrying route (direction along the opening direction of the clearance S) by the forward/backward moving mechanism 40 disposed at the holder 24. The guide bar 34 is configured in such a way that the position of the guide face 32 of the guide bar facing 30 can be adequately adjusted with respect to the work material W according to the diameter of the work material W or the wear-out or the like of the guide bar facing 30.

The guide bar facing 30 is formed of a cast iron or the like in an approximately rectangular flat plate set softer than the work material W so as not to scratch the work material W, and is arranged so that the long side extends in a direction along the carrying route (see FIG. 1). A taper 31, which is inclined in such a way as to be apart from the carrying route toward the inlet side or the outlet side of the straightening roll 12, 14, is formed at a corner portion of each guide bar facing 30 which is to be the inlet side or the outlet side of the straightening roll 12, 14 to permit adequate guiding of the work material W to the carrying route and prevent the work material W from being scratched by the sharp comers of the guide bar facing 30.

The pair of guide bar facings 30, 30 are disposed according to the areas of the carrying route in both straightening rolls 12, 14. A first guide bar facing 30 a and a second guide bar facing 30 b disposed facing each other with the carrying route in between are provided in the inlet-side areas in the straightening rolls 12, 14. A third guide bar facing 30 c and a fourth guide bar facing 30 d disposed facing each other with the carrying route in between are provided in the outlet-side areas. That is, the straightening rolls 12, 14 are configured in such a way that the work material W is guided by the pair of guide bar facings 30, 30 disposed facing each other with the carrying route in between in each of the two separated inlet-side and outlet-side areas of the carrying route.

The guide bar facings 30 are each arranged askew to the horizontal carrying face PL of the work material W by a predetermined angle (layout angle) θ with the carrying route being an axis, along the opening direction of the clearance S which is defined by the lower straightening roll 12 and the upper straightening roll 14 so as not to interfere with both straightening rolls 12, 14. The guide bar facings 30 are linearly inserted in the clearance S along the opening direction of the clearance S so that the guide plane 32 or the front end face of the guide bar facing 30 faces the carrying route in parallel and guides the work material W along the carrying route. The pair of guide bar facings 30, 30 are positioned above the same inclined surface. That is, in the straightening rolls 12, 14 which are disposed one above the other and arranged so as to cross each other to the carrying route, the guide bar facing 30 is arranged obliquely extending upward in an area where the upper face of the body portion of the lower straightening roll 12 is eccentrically present outward to the upper straightening roll 14 (direction away from the carrying route), while the guide bar facing 30 is arranged obliquely extending downward in an area where the lower face of the body portion of the upper straightening roll 14 is eccentrically present outward to the lower straightening roll 12 (direction away from the carrying route).

In the embodiment, as shown in FIG. 4, in the inlet-side area of the straightening roll 12,14, the first guide bar facing 30 a is inserted in the clearance S between both straightening rolls 12, 14 open in an obliquely left downward direction in such a way that the first guide bar facing 30 a is inclined obliquely left downward direction as the first guide bar facing 30 a moves away from the carrying route, and the second guide bar facing 30 b is inserted in the clearance S between both straightening rolls 12, 14 open in an obliquely right upward direction, in symmetry with the first guide bar facing 30 a with the carrying route in between, in such a way that the second guide bar facing 30 b is inclined obliquely right upward direction as the second guide bar facing 30 b moves away from the carrying route. Both guide bar facings 30 a and 30 b are arranged on the same inclined face. Further, in the outlet-side area, the third guide bar facing 30 c is inserted in the clearance S between both straightening rolls 12, 14 open in an obliquely right downward direction in such a way that the third guide bar facing 30 c is inclined obliquely right downward direction as the third guide bar facing 30 c moves away from the carrying route, and the fourth guide bar facing 30 d is inserted in the clearance S between both straightening rolls 12, 14 open in an obliquely left upward direction, in symmetry with the third guide bar facing 30 c with the carrying route in between, in such a way that the forth guide bar facing 30 d is inclined obliquely left upward direction as the fourth guide bar facing 30 d moves away from the carrying route. Both guide bar facings 30 c and 30 d are arranged on the same inclined face. The pair of guide bar facings 30 a, 30 b arranged in the inlet-side area for the straightening rolls 12, 14 and the pair of guide bar facings 30 c, 30 d arranged in the outlet-side area thereof are symmetrical to each other.

In consideration of the shape of each straightening roll 12, 14, the angle of intersection of both straightening rolls 12, 14, or the extending width of the guide bar facing 30 with respect to the carrying route and the thickness of the guide bar facing 30, the layout angle θ of the guide bar facing 30 with respect to the carrying face PL is so set as not to interfere with both straightening rolls 12, 14, preferably in a range of ±10 to ±20°. The guide bar 34 constituting the material guide means 28 and the forward/backward moving mechanism 40 which holds the guide bar 34 are provided at the holder 24 at substantially the same layout angle as each guide bar facing 30, and can linearly move the associated guide bar facing 30 forward and backward toward the work material W (direction to cross the carrying route) via the clearance S (see FIG. 4). With the guide bar facing 30 moved forward/backward, the guide plane 32 of the guide bar facing 30 which faces the carrying route in parallel is moved while keeping the relative positional relationship (parallel relationship) with the work material W. Each material guide means 28 is provided with position detecting means 58 which detects the position of the guide plane 32 of the guide bar facing 30 which faces the carrying route in the associated guide bar facing 30.

At the time the work material W is fed between both straightening rolls 12, 14, the work material W is twisted in a predetermined direction according to the rotational direction of the straightening rolls 12, 14, and tends to move in an oblique direction on the carrying face PL from the carrying route (see the solid arrows in FIG. 1). That is, the degree of slide contact of one of the guide bar facings 30 corresponding to the direction of movement caused by twisting of the work material W with respect to the work material W is considered greater as compared with the paired other guide bar facing 30. Accordingly, in the embodiment, the guide faces 32 of the first guide bar facing 30 a positioned on the inlet side of the work material W with respect to the straightening rolls 12, 14 and corresponding to the direction of movement caused by twisting of the work material W and the third guide bar facing 30 c positioned on the outlet side and corresponding to the direction of movement caused by twisting of the work material W are formed wider in the direction along the carrying route than the guide faces 32 of the other respectively paired guide bar facings 30 b, 30 d. Therefore, the guide bar facings 30, 30 adjoining along the carrying route from the planar view in FIG. 1 are configured to be eccentric to the inlet side or the outlet side, not the way to separate carrying-route holding areas at the center portions of the straightening rolls 12, 14.

As shown in FIG. 3, the forward/backward moving mechanism 40 of the embodiment employs a so-called screw feeding mechanism basically comprising a screw shaft 42 which rotates forward and backward in response to the action of drive means 50, and a nut portion 44 fastened on the screw shaft 42 and coupled to the guide bar 34. The forward/backward moving mechanism 40 is coupled to a cylindrical casing 46 which serves as an outer hull with the guide bar 34 fitted in the casing 46 in a forward and backward movable manner and the nut portion 44 coupled to the rear end portion of the guide bar 34 (the opposite side to the coupling end to the guide bar facing 30) with its rotation being restricted. The screw shaft 42 is put through the casing 46 in a rotatable manner with their axes aligned with each other. One end of the screw shaft 42 is fastened into the nut portion 44 and a screw shaft gear 48 secured to the other end of the screw shaft 42 is engaged with a drive gear 52 secured to the drive shaft of the drive means 50 like a hydraulic motor. A pair of key grooves 54, 54 extending in the direction to cross the carrying route are provided in the circumferential surface of the guide bar 34 fitted in the casing 46 at symmetrical positions, and a key 56 fixed to the casing 46 is fitted in each key groove 54 to prevent rotation of the guide bar 34 and permit the forward/backward movement in the direction to cross the carrying route. That is, as the drive means 50 is rotated, the screw shaft 42 is rotated in a predetermined direction via both gears 48, 52, and the guide bar 34 is moved forward and backward in the direction to cross the carrying route along the inner circumferential surface of the casing 46 with the screw shaft 42 and the nut portion 44 fastened together, so that the position of the guide bar facing 30 with respect to the carrying route can be adjusted. The whirl-stop mechanism of the forward/backward moving mechanism 40 including the key grooves 54 and the keys 56 may be configured in such a way that the key groove is formed in the casing 46 and the key is fixed to the guide bar 34 in association therewith.

Operation of Embodiment

Next, the operation of the straightener according to the embodiment will be explained. At the time of straightening the work material W, the work material W is let to pass between the straightening faces (circumferential surfaces of the body portions) of the lower and upper straightening rolls 12, 14 with the lower and upper straightening rolls 12, 14 with the guide bar facing 30 of each material guide means 28 being held adjusted at predetermined positions. In this process, the straightening rolls 12, 14 perform required straightening while rotating the work material W, and the paired guide bar facings 30, 30 guide the feeding of the work material W while restricting the horizontal fluctuation thereof, thereby straightening kinks, bends or the like of the entire work material W.

Because both straightening rolls 12, 14 oppositely disposed one above the other are arranged in an X pattern with their axes intersecting each other and both straightening rolls 12, 14 are formed in a recessed tsuzumi shape, the opening direction of the clearance S defined by both straightening rolls 12, 14 faces in an oblique direction in the inlet-side area with the carrying route being the axis with respect to the carrying face PL (see FIG. 5(a)), gradually faces in a horizontal direction toward the intersection (center portion) of the roll axes (see FIG. 5(b)), and faces in an oblique direction symmetrical to the inlet-side area toward the outlet-side area from the center portion (see FIG. 5(c)). In this manner, the opening direction of the clearance S defined by the lower and upper straightening rolls 12, 14 changes according to the areas along the carrying route.

In the straightener according to the present invention, the pair of guide bar facings 30, 30 are respectively disposed in the inlet-side area and the outlet-side area for the work material W in both straightening rolls 12, 14, and each guide bar facing 30 is arranged inclined in an oblique direction by a predetermined layout angle θ with respect to the horizontal carrying face PL for the work material W with the carrying route being the axis in consideration of the width of the guide bar facing 30 along the carrying route, and the opening direction of the clearance S, so that the guide bar facing 30 is linearly inserted in the clearance S along the opening direction thereof to let the guide plane 32 come close to the carrying route without interference with both straightening rolls 12, 14. As each guide bar facing 30 is arranged askew to the carrying face PL along the opening direction of the clearance S in such a way as not to interfere with both straightening rolls 12, 14 in this manner, the guide plane 32 of the guide bar facing 30 which is formed approximately like a rectangular flat plate can be made to face the carrying route in parallel via the clearance S. That is, each guide bar facing 30 need not have a complicated three-dimensional shape taking the interference with both straightening rolls 12, 14 into account, and can have a simple shape like an approximately rectangular flat plate. This makes it possible to easily form the guide bar facing 30 itself, eliminate a processing work and reduce the manufacturing cost. Further, the guide bar facing 30 can be made lighter, thereby improving the handleability in a replacement work or the like.

As the straightening work progresses, each guide bar facing 30 which guides the work material W wears out, lowering the performance of guiding the work material W, the guide bar facing 30 is configured so as to be moved forward by the forward/backward moving mechanism 40 by a given amount based on the detection done by the position detecting means 58 or with the passage of time, so that the work material W is always guided in a desirable state. The carrying route is separated to front and rear areas by the pair of guide bar facings 30, 30 for guidance, and each guide bar facing 30 is so configured as to be movable forward and backward by the forward/backward moving mechanism 40. This provides an advantage such that the position of the guide bar facing 30 with respect to the carrying route can be finely adjusted according to the degree of wearing or the like of the guide bar facing 30 which guides the work material W through each area.

Because each guide bar facing 30 is formed like an approximately flat plate and is linearly moved by the forward/backward moving mechanism 40, even with the forward and backward movement of the guide bar facing 30, the maximum friction tolerance can be set within the range of the size of the guide bar facing 30 in the direction to cross the carrying route without interfering with both straightening rolls 12, 14. This makes it possible to elongate the life of the guide bar facing 30 and reduce the frequency of replacement of the guide bar facing 30. Because the guide bar facing 30 is so configured as to be linearly moved forward and backward by the forward/backward moving mechanism 40, the relative positional relationship between the guide plane 32 of the guide bar facing 30 and the work material W, which is set to a parallel positional relationship, does not change and core misalignment does not occur even with the forward and backward movement of the guide bar facing 30, so that the work material W is always guided in a desirable state. Therefore, the straightener of the embodiment can continuously carry out a precise straightening work.

Two sets of guide bar facings 30, 30 are disposed along the carrying route and the carrying route corresponding to the straightening rolls 12, 14 is separated into the inlet-side area and the outlet-side area by the pair of guide bar facings 30, 30 adjoining each other from the planar view to divide the burden of the guiding of the work material W. That is, because one of the guide bar facings 30 which corresponds to the direction of movement caused by twisting of the work material W wears out faster than the other paired guide bar facing 30, each guide bar facing 30 can be replaced as needed according to the degree of progress of wearing. Further, because the guide plane 32 of one of the guide bar facings 30 which corresponds to the direction of movement caused by twisting of the work material W is formed wider in the direction along the carrying route than the guide plane 32 of the other paired guide bar facing 30, the service life of that one guide bar facing 30 which has a larger degree of slide contact with the work material W can be made longer, and the work material W can be guided desirably.

Furthermore, regarding the guide bar facing 30 that wears out and needs replacement, as the forward/backward moving mechanism 40 is driven reversely to move the guide bar facing 30 away from the carrying route and the straightening rolls 12, 14 and the holder 24 is turned outward around the columnar support 20, the guide bar facing 30 can be pulled outward according to the holder 24. Then, the guide bar facing 30 is removed from the front end face of the guide bar 34 and replaced with a new one, after which the reverse procedures to those mentioned are carried out to facilitate replacement of the guide bar facing 30. The reduced weight of the guide bar facing 30 makes the replacing work easier.

As mentioned above, the forward/backward moving mechanism 40 of the embodiment that uses the screw feeding mechanism has the whirl-stop mechanism including the key grooves 54 and the keys 56 fitted in to the key groove 54, so that at the time of forward and backward movement of the guide bar 34, the guide bar 34 does not rotate, thus preventing interference of the guide bar facing 30 with the straightening rolls 12, 14 and allowing the guide plane 32 to always face the carrying route in parallel thereto.

Although the lower and upper straightening rolls 12, 14 combined are formed in such a way that the circumferential surfaces of the body portions are formed like a tsuzumi shape dented in the axial direction in the embodiment, the structure of the guide bar facing in the straightener according to the present invention can be adapted to such a structure that one straightening roll is formed like a drum whose body portion has a circumferential surface protruding in the radial direction.

The forward/backward moving mechanism 40 that moves the guide bar facing 30 forward and backward in the direction to cross the carrying route is not limited to the screw feeding mechanism, and may use a fluid cylinder, such as a hydraulic cylinder, or other link mechanisms or the like.

FIG. 6 is a plan view showing material guide means 60 provided at the holder 24 in the straightener of the modification, and FIG. 7 is a side view thereof. Although the foregoing description of the embodiment has been given of the material guide means 28 having the forward/backward moving mechanism 40 with the guide bar 34 so configured as to be automatically movable forward and backward by the drive means 50 like a motor, the material guide means 60 of the modification has a forward/backward moving mechanism 62 which can manually move the guide bar 34 forward and backward. The forward/backward moving mechanism 62 of the modification employs a so-called screw feeding mechanism basically including a screw shaft 66 which rotates forward and backward in response to movement of a wheel 64, and a nut portion 68 which is fastened on the screw shaft 66 and secured to the holder 24. The distal end portion of the screw shaft 66 which extends from the nut portion 68 is engaged with the rear end portion of the guide bar 34 (the opposite side to the coupling end of the guide bar facing 30) held to a casing 70 in a forward and backward movable manner, and moves the guide bar 34 forward and backward in the direction to cross the carrying route according to the forward and backward movement of the screw shaft 66. The guide bar facing 30 attached to the front end face of the guide bar 34 is arranged askew in an oblique direction to the horizontal carrying face PL for the work material W by a predetermined layout angle θ with the carrying route being the axis, so that the guide bar facing 30 is linearly inserted in the clearance S along the opening direction of the clearance S to make the guide plane 32 movable close to and away from the carrying route without interfering with both straightening rolls 12, 14. That is, as the wheel 64 is turned, the screw shaft 66 is rotated in a predetermined direction and the screw shaft 66 fastened with the nut portion 68 causes the guide bar 34 to move forward and backward in the direction to cross the carrying route, so that the position of the guide bar facing 30 attached to the front end face of the guide bar 34 with respect to carrying route can be adjusted. While the rotational direction of the straightening roll of the straightener of the modification is reverse to that of the embodiment and the layout positions of the guide bar facings 30 differ accordingly, the other structures are the same as those of the embodiment.

The material guide means 60 having guide bar facings 30 a, 30 c set wider in the moving direction of the work material W which is twisted according to the feeding of the work material W by both straightening rolls 12, 14 has a plurality of forward/backward moving mechanisms 62 mentioned above. A pair of forward/backward moving mechanisms 62, 62 are disposed apart from each other in a direction along the moving direction of the guide bar facings 30 a , 30 c in association with the forward side and rear side of the guide bar facing 30 a, 30 c in the moving direction to move the forward side and rear side of the guide bar facing 30 a, 30 c forward and backward, respectively. This makes it possible to not only move the guide plane 32 forward and backward in parallel to the carrying route but also position the front side or the rear side inclined and apart from the carrying route. With a plurality of forward/backward moving mechanisms 62, 62 provided this way, the guide plane 32 of the guide bar facing 30 a, 30 a can be adjusted to a more adequate position with respect to the work material W not only by causing the guide plane 32 of the guide bar facing 30 a, 30 c to face the carrying route in parallel but also independently moving the forward/backward moving mechanism 62 on the front side or the rear side according to the local wearing of the guide plane 32 of the guide bar facing 30 a, 30 a that is caused as the straightening work progresses. 

1. A straightener having a pair of straightening rolls (12, 14) facing each other, one above the other, with a carrying route for a work material (W) in between, provided so as to cross each other at a predetermined angle to the carrying route, and formed in a tsuzumi shape having at least one circumferential surface recessed, and a pair of guide bar facings (30, 30) which are disposed facing each other along the carrying route for the work material (W) so as to intersect an opposing direction of the straightening rolls (12, 14) and guide the work material (W), with a clearance (S) formed between both straightening rolls (12, 14) and opening in a direction orthogonal to a line connecting axes of the straightening rolls (12, 14) to each other in a plane orthogonal to the carrying route, characterized in that the pair of guide bar facings (30, 30) are each formed in an approximately rectangular flat plate and are respectively provided at an inlet-side area and an outlet-side area of both straightening rolls (12, 14) for the work material (W), each of the guide bar facings (30) is disposed askew to a horizontal carrying face (PL) of the work material (W) along an opening direction of the clearance (S) so as not to interfere with both straightening rolls (12, 14), and guide faces (32) of the guide bar facings (30) for the work material (W) are formed in such a way that the guide bar facings (30) are linearly movable forward and backward along the opening direction of the clearance (S) relative to the carrying route in a state where the guide faces (32) face the carrying route in parallel to each other through the clearance (S).
 2. The straightener according to claim 1, wherein a layout angle (θ) of the guide bar facings (30) to the carrying face (PL) is set in a range of ±10 to ±20°.
 3. The straightener according to claim 1 or 2, wherein the guide face (32) of one of the guide bar facings (30) which corresponds to a direction of movement caused by twisting of the work material (W) is formed wider along the carrying route than the guide face (32) of the other paired guide bar facing (30).
 4. The straightener according to claim 1 or 2, wherein each of the guide bar facings (30) is coupled via a guide bar (34) to a forward/backward moving mechanism (40) which has a whirl-stop mechanism (54, 56) so that when the guide bar facing (30) is moved forward and backward along the opening direction of the clearance (S) by the forward/backward moving mechanism (40), the guide bar facing (30) is prevented from rotating in relative to the carrying route.
 5. The straightener according to claim 3, wherein each of the guide bar facings (30) is coupled via a guide bar (34) to a forward/backward moving mechanism (40) which has a whirl-stop mechanism (54, 56) so that when the guide bar facing (30) is moved forward and backward along the opening direction of the clearance (S) by the forward/backward moving mechanism (40), the guide bar facing (30) is prevented from rotating in relative to the carrying route. 